Disklike recording media, a method for detecting forged disks, an anti-forgery system for performing a true-false judgment based on information collected from the recording media, and a manufacturing apparatus for recording information in the disks

ABSTRACT

A recording medium includes first information selected from a plurality of information patterns and second information selected from another plurality of information patterns for the true-false judgement. A true-false judging device performs a statistic analysis when any coincidence is found between the readout combination of the first and second information and registered combination patterns, to identify an inspected recording medium as a forged product based on the result of the statistic analysis.

BACKGROUND OF THE INVENTION

The present invention relates to disklike recording media, such as CD(i.e., compact disk) and DVD (i.e., digital video disk or digitalversatile disk), which are suitable for mass production and wide-arealdistribution. More specifically, the present invention relates to ananti-forgery system, and related detecting apparatuses installable inthe distribution channel or in a center office equipped with a hostcomputer. Moreover, the present invention relates to a manufacturingmethod and apparatus for recording the information for a true-falsejudgement on the surfaces of the disk.

The conventional CD is preferably used for recording the audioinformation or program. The conventional VHD or LD is preferably usedfor recording video or image information. However, a recently developedDVD has a very large recording capacity which is approximately 5 to 7times the recording capacity of the above-described conventional disks.Thus, the CD, VHD and LD will be replaced by DVD-Audio and DVD-Video.

In other words, the high-density recording media can provide an addedvalue due to their large recording capacity. On the other hand, theindustrial damage and monetary loss will be very large if they aresubjected to the forgery.

SUMMARY OF THE INVENTION

An object of the present invention is to provide an anti-forgery systemcapable of accurately detecting forged products of the disklike recodingmedia at an earlier stage of the circulation of the forged products.

In order to accomplish the above and other related objects, one aspectof the present invention provides a recording medium comprising firstinformation selected from a plurality of information patterns for atrue-false judgement, and second information selected from anotherplurality of information patterns for the true-false judgement.

Preferably, the recording medium has a disklike body with a firstsurface on which the first information is recorded and a second surfaceon which the second information is recorded. In this case, the firstinformation may be a pit or groove pattern formed on the first surface.A registered combination pattern of an enciphered format may be recordedon a specific area of a disk surface other than the first informationand the second information. The first information and the secondinformation are combined randomly.

Another aspect of the present invention provides a system for detectingforged products of recording media. This system comprises a readingmeans for reading first information and second information from aninspected recording medium, a memory means for storing a plurality ofregistered combination patterns for a true-false judgement, and atrue-false judging means for identifying the inspected recording mediumas a forged product when no coincidence is found between a readoutcombination of the first and second information and the registeredcombination patterns.

Preferably, the true-false judging means is for further performing astatistic analysis when any coincidence is found between the readoutcombination and the registered combination patterns, thereby identifyingthe inspected recording medium as a forged product based on the resultof the statistic analysis.

Preferably, in the statistic analysis, the true-false judging means isfor detecting a combination pattern of the first and second informationrecorded on the forged product with reference to a standard deviation ora time differential value of the standard deviation.

Another aspect of the present invention provides an apparatus fordetecting forged products of recording media. This apparatus comprises areading means for reading first information and second information froman inspected recording medium, a transmitting means for transmitting areadout combination of the first and second information to a true-falsejudging apparatus, a receiving means for receiving a true-falsejudgement result from the true-false judging apparatus, and an outputmeans for outputting the true-false judgement result.

Preferably, the readout combination of the first and second informationis transmitted to the true-false judging apparatus by using acommunication device and related communication software. The apparatusmay be a playback apparatus of the disklike recording medium.

Another aspect of the present invention provides an apparatus fordetecting forged products of recording media. This apparatus comprises amemory means for storing a plurality of registered combination patternsfor a true-false judgement, a receiving means for receiving acombination of first and second information read out from an inspectedrecording medium, and a true-false judging means for identifying theinspected recording medium as a forged product when no coincidence isfound between the readout combination of the first and secondinformation and the registered combination patterns.

In this case, the true-false judging means is for further performing astatistic analysis when any coincidence is found between the readoutcombination and the registered combination patterns, so as to identifythe inspected recording medium as a forged product based on the resultof the statistic analysis. The true-false judging means is for detectinga combination pattern of the first and second information recorded onthe forged product with reference to a standard deviation or a timedifferential value of this standard deviation.

Moreover, another aspect of the present invention provides amanufacturing apparatus for a disklike recording medium. Thismanufacturing apparatus comprises a first recording means for recordingmain information including first information on a first surface of thedisklike recording medium, and a second recording means for recordingsecond information on a second surface of the disklike recording medium.Each of the first and second information is selected from a plurality ofinformation patterns for a true-false judgement.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the presentinvention will become more apparent from the following detaileddescription which is to be read in conjunction with the attacheddrawings, in which:

FIG. 1 is a perspective view showing a recording disk and an apparatusfor detecting forged products in accordance with a preferred embodimentof the present invention;

FIG. 2 is a view illustrating an example of combined true-false judginginformation to be recorded in the disk shown in FIG. 1;

FIG. 3 is a block diagram showing an essential arrangement of a forgedproduct detecting system in accordance with the preferred embodiment ofthe present invention;

FIG. 4 is a flowchart illustrating the details of a true-false detectionin accordance with the preferred embodiment of the present invention;

FIG. 5 is a view illustrating an example of the statistic processing forcounting the agreement of the combination of the true-false judginginformation in accordance with the preferred embodiment of the presentinvention;

FIG. 6 is a histogram showing the relationship between the type of diskand its occurrence;

FIG. 7 is a histogram showing the relationship between the type of diskand its occurrence;

FIG. 8 is a histogram showing the relationship between the type of diskand its occurrence;

FIG. 9 is a histogram showing the relationship between the type of diskand its occurrence;

FIG. 10 is a graph showing the history of the variation in the standarddeviation;

FIG. 11 is a graph showing the history of the variation in the timedifferential value of the standard deviation;

FIG. 12 is a view showing a relationship between a distribution channelof disks and a forged product detecting system in accordance with thepreferred embodiment of the present invention;

FIG. 13 is a flowchart showing the processing performed at a terminal ofthe wholesale or retail shop shown in FIG. 12 in accordance with thepreferred embodiment of the present invention;

FIG. 14 is a flowchart showing the processing performed in adistribution administrating center shown in FIG. 12 in accordance withthe preferred embodiment of the present invention;

FIG. 15 is a flowchart showing the processing performed at a terminal ofa customer shown in FIG. 12 in accordance with the preferred embodimentof the present invention;

FIG. 16 is a flowchart showing another processing performed in thedistribution administrating center shown in FIG. 12 in accordance withthe preferred embodiment of the present invention;

FIG. 17 is a view showing another relationship between the distributionchannel of the disks and a forged product detecting system in accordancewith the preferred embodiment of the present invention;

FIG. 18 is a side cross-sectional view showing a compact disk inaccordance with the preferred embodiment of the present invention;

FIG. 19 is a side cross-sectional view showing a digital versatile diskin accordance with the preferred embodiment of the present invention;

FIG. 20 is a side cross-sectional view showing another digital versatiledisk in accordance with the preferred embodiment of the presentinvention;

FIG. 21 is a side cross-sectional view showing another digital versatiledisk in accordance with the preferred embodiment of the presentinvention;

FIG. 22 is a side cross-sectional view showing a read only HDTV disk inaccordance with the preferred embodiment of the present invention;

FIG. 23 is a block diagram showing a disk manufacturing system inaccordance with the preferred embodiment of the present invention; and

FIG. 24 is a block diagram showing another disk manufacturing system inaccordance with the preferred embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, preferred embodiments of the present invention will beexplained with reference to the attached drawings.

FIG. 1 is a perspective view showing a recording disk and an apparatusfor detecting forged products in accordance with a preferred embodimentof the present invention. In FIG. 1, a disk 1 has a first surface onwhich main information is recorded. The main information includes afirst image “A” which is used in a true-false judgement for each disk.The disk 1 has a second surface on which a second image “B” is formed.The second image “B” is also used in the true-false judgement. Thesecond image “B” and the main information including the first image “A”are read by a CCD line sensor 2 and a pickup lens 3, respectively. Thedata on the disk 1 is scanned when the disk 1 is rotating while the CCDline sensor 2 and the pickup lens 3 are stationarily fixed. The CCD linesensor 2 and the pickup lens 3, cooperatively serving as a readingdevice, can be replaced by any other optical, magnetic, magneto-optical,or capacitance sensors or devices having the equivalent function. Theimages “A” and “B” can be replaced by any other bar codes, characters,enciphered codes when the reading device can read or discriminate them.The true-false judgement information may be scrambled or mixed withother information so as not to be discriminable at a glance.

FIG. 2 shows simple samples of the true-false judgement information. Thefirst image “A”, serving as main information, is a mammoth portrait. Thesecond image “B”, serving as print information, is a clover mark. Atotal of five different patterns are prepared for each of the first andsecond images “A” and “B,” so that one of them is arbitrarily selectedas a true-false judgement information. According to this embodiment, thefirst image “A” is selectable from the group consisting of the mammoth,elephant, giraffe, ant eater, and horse portraits. The second image “B”is selectable from the group consisting of the clover, four-leaf clover,heart, spade, and diamond marks. Accordingly, this embodiment provides25 (=5×5) patterns as the registered or authorized combinations of thefirst and second images “A” and “B.” In other words, the patternrecorded in each disk 1 is one of the 25 registered or authorizedpatterns, with each pattern having an equal possibility (i.e., 1/25) tobe selected.

The first images “A” may resemble each other but different in someportions so that the third party cannot find the difference betweenthem. Similarly, the second images “B” may resemble each other butdifferent in some portions.

FIG. 3 is a schematic arrangement of a forged product detecting system.A main information reading section 4 reads the main information (i.e.,first image “A”) recorded on the disk 1. A print information readingsection 5 reads the print information (i.e., second image “B”) printedon the disk 1. Each readout image is processed by using an appropriateimage recognition software (not shown). A true-false judging section 6receives the first image “A” from the main information reading section 4and the second image “B” from the print information reading section 5.Based on a combination of the readout images “A” and “B”, the true-falsejudging section 6 performs first and second true-false judgements shownin FIG. 4. The true-false judging section 6 comprises a CPU 10performing the true-false judgements, and associated memories ROM 11 andRAM 12. The ROM 11 stores a total of 25 registered or authorizedpatterns α (i.e., 11, 12, 13, - - - , 54, 55) as possible combinationsof the first and second images “A” and “B.” Furthermore, the ROM 11stores a rule β for judging the circulation of forged products. The RAM12 stores the history of readout combined image patterns by counting theoccurrence of respective patterns 11, 12, 13, - - - , 54, 55.

In the flowchart shown in FIG. 4, the initialization is performed in astep S1. Then, the images “A” and “B” are read from the disk 1 to beinspected in a step S2. Then, the true-false judging section 6 performsthe first true-false judgement. More specifically, the combination ofthe readout images “A” and “B” is compared with the image patterns astored in the ROM 11 in a step S3. If no coincidence is found (NO in thestep S3), it is concluded in a step S4 that the inspected disk 1 is aforged product. If any coincidence is found (YES in the step S3), thetrue-false judging section 6 performs the second true-false judgement.More specifically, in a step S5, the detected combination of the readoutimages “A” and “B” is classified into the corresponding one of the 5×5patterns of the image patterns α. Then, in a step S6, the RAM 12increments a count value of the identified pattern as shown in FIG. 5.At the same time, a total disk number “N” is increased by 1. Then, theupdated classification data is statistically processed in a step S7.

FIG. 6 is a histogram showing the relationship between the pattern ofdisk and the frequency of occurrence which is typically observed in aninitial stage of the circulation of disks (e.g., N=250). FIG. 7 is ahistogram showing the occurrence of the disk patterns observed when thetotal disk number “N” is increased (e.g., N=2,500). As apparent fromFIG. 7, the frequency of occurrence in each disk pattern issubstantially uniform when the 25 patterns are randomly used.

It is now assumed that circulation of forged products is started afterthe passage of a significant leading time. Many of the forged productscontain the main information with no (or incomplete) print information.This kind of forged products can be easily checked by theabove-described first true-false judgement. However, the firsttrue-false judgement is no longer reliable when the forged products haveperfect print information. In such a case, the circulation of the forgedproducts can be detected by the increase of a particular disk pattern.

FIG. 8 is a histogram showing the occurrence of the disk patternsobserved when the total disk number “N” is further increased (e.g.,N=7,500). In this case, the occurrence of the pattern “43” is largerthan other patterns by approximately 50. This is a sort of signindicating the presence of forged products. From this sign, it isbelieved the circulation of forged products has just begun. On the otherhand, this may be an accidental phenomenon.

Accordingly, in the step S7 of the flowchart shown in FIG. 4, thestatistic analysis is performed to confirm the presence of the forgedproducts. For example, the circulation of the forged products isconfirmed when the occurrence n_(ij) of a specific disk pattern (ij) islarger than the average occurrence n₀ of other patterns by apredetermined threshold. The rule β stored in the ROM 11 determines thispredetermined threshold (e.g., 3σ). Thus, in a step S8, it is checkedwhether the value (n_(ij)−n₀) is equal to or larger than 3σ, where arepresents a standard deviation. The occurrence n₄₃ of the pattern “43”shown in FIG. 8 does not yet exceed 3σ. Thus, the decision of the forgedproduct circulation is postponed in a step S9.

FIG. 9 is a histogram showing the occurrence of the disk patternsobserved when the total disk number “N” is 12,500. In this case, theoccurrence n₄₃ of the pattern “43” is larger than the average occurrencen₀ of other patterns by approximately 800. The difference 800 issufficiently larger than 3σ. Thus, it is concluded that approximately800 forged products have been already circulated in the market at thistiming (step S10).

Although the above-described threshold (e.g., 3σ) is read out from theROM 11, it is possible to arbitrarily modify the readout thresholdaccording to the intent of the user. For example, the threshold based onthe rule β can be modified considering the total disk number “N.”Therefore, the judgement of the forged products may be made when thenumber of disks having a certain pattern exceeds 800 with respect to thetotal disk number N=13,300. If the threshold is reduced to 2σ, theforged products will be detected at an earlier stage although theaccurateness in the true-false judgement will be worsened.

It is preferable to monitor the statistic data periodically for each ofthe patterns (i.e., 5×5=25 patterns). FIG. 10 shows the change ortransition of the standard deviation σ in relation to the passage oftime (date), which is observed on a certain pattern. The noise rate ishigh in the initial stage since the total number of the disks circulatedin the market is small. Accordingly, it is preferable to cancel thejudgement during the initial stage (i.e., during the noise period). Thestandard deviation a then decreases and stabilizes at a constant valueafter the noise period has passed. In other words, the time differentialvalue of the standard deviation (i.e., dσ/dt) gradually converges at 0as the total disk number increases. However, once the forged productsstart circulating in the market, the standard deviation σ startsincreasing correspondingly. Its time differential value dσ/dt alsoincreases rapidly toward a positive direction. Thus, the circulation ofthe forged products is sensitively detectable based on the timedifferential value dσ/dt. Furthermore, although the system may becomplicated, it will be possible to detect the presence of the forgedproducts by statistically monitoring the publication of the disk 1 withreference to the standard deviation σ and its differential value dσ/dt.

Accordingly, this embodiment makes it possible to surely detect theforged products regardless of sophistication in the forging technology.Furthermore, it is possible to accurately specify the pattern assignedto the forged disk. Only the software maker and the authorizedmanufactures can know the details of the first image “A” and the secondimage “B” and their combination patterns. It is impossible for the thirdparties to manufacture a great amount of forged products without beingchecked by the above-described true-false judgements. Even if the thirdparties know the presence of the first and second images “A” and “B”, itwill take a long time to analyze the details of the concealed diskpatterns and distribution ratio of each combination and will benecessary to invest a great amount of money to prepare the samepatterned disks.

Although 25 (=5×5) patterns are prepared for the images “A” and “B” inthe above-described embodiment, it is possible to change the number ofcombinations. Increasing the total number of combinations is effectiveto detect forged products in an earlier stage. Although the preparedpatterns are randomly or uniformly assigned to the disks in theabove-described embodiment, it is possible to intentionally change thedistribution ratio of each combined disk patterns. For the thirdparties, analyzing the intentionally-determined distribution ratio willbe a more-complicated and time-consuming work.

FIG. 12 shows a distribution channel of the disk 1 when the disk 1 is aread-only disk, such as CD or DVD. A software maker 101, who is acopyright holder, produces the software to be distributed. A diskmanufacturer 102 produces the disks 1 in response to the request fromthe software maker 101. The mass produced disks 1 are sent to awholesaler 103. The wholesaler 103 distributes the disks 1 to a retailer104, such as a software shop, a disk shop, a record shop, or an electricappliance shop. A customer 105 buys the disk 1 at the retailer 104. Theforger 106 invades somewhere in this distribution channel to circulatethe forged products.

The true-false detecting apparatus performing the processing shown inFIG. 4 is placed in each of the wholesaler 103 and the retailer 104 todetect the forged products by checking all or part of the disks handledby them. Accordingly, the presence of the forged products is notifiedfrom the wholesaler 103 or the retailer 104 to the software maker 101 orthe disk manufacturer 102. A distribution administrating center 100collects the information from the true-false detecting apparatusinstalled in each of the wholesaler 103 and/or the retailer 104.Accordingly, the presence of the forged products is checked by thedistribution administrating center 100. Establishing the distributionadministrating center 100 is advantageous when the disks are distributedthrough numerous franchised shops which may be located nationwide orworldwide. It will be easy to check a wide-area circulation of theforged products.

In the arrangement shown in FIG. 12, the distribution administratingcenter 100 communicates with the terminals (i.e., the true-falsedetecting apparatuses) in the wholesaler 103 and/or the retailer 104 viaradio or cable communication lines.

FIG. 13 is a flowchart showing the processing performed in each terminalof the wholesaler 103 and/or the retailer 104. First, in a step S11, theinitialization is performed. Then, in a step S12, the images “A” and “B”are read from the disk 1 to perform the true-false judgement. Then, in astep S13, the communication line is connected between the terminal andthe distribution administrating center 100. In a step S14, the detectedcombination of the images “A” and “B” is transmitted to the distributionadministrating center 100. The distribution administrating center 100checks the received information with the registered data. Then, thedistribution administrating center 100 returns the inspection result tothe terminal. Thus, in a step S15, the terminal receives an answersignal of “YES” or “NO” returned from the distribution administratingcenter 100. Then, in a step S16, the terminal notifies an operator ofthe true-false judgement result through a display unit.

FIG. 14 is a flowchart showing the processing performed in thedistribution administrating center 100. The distribution administratingcenter 100 comprises CPU 10, ROM 11 and RAM 12 having the same functionsas those of the true-false judging section 6 disclosed in FIG. 3. Thedistribution administrating center 100 receives the information from theterminal in a step S20 to perform the first true-false judgement. Thecombination of the images “A” and “B” transmitted from the terminal iscompared with the image patterns α, i.e., 25 (=5×5) patterns, stored inthe ROM 11 in a step S21. If no coincidence is found (NO in the stepS21), it is concluded that the inspected disk 1 is a forged product.Thus, in step S22, the distribution administrating center 100 returnsthe inspection result “NO” to the terminal (refer to the step S15 in theflowchart of FIG. 13).

If any coincidence is found (YES in the step S21), the distributionadministrating center 100 performs the second true-false judgement. Morespecifically, in a step S23, the detected combination of the transmittedimages “A” and “B” is classified into the corresponding one of the 5×5patterns of the image patterns α. Then, in a step S24, the RAM 12increments a count value of the identified pattern as shown in FIG. 5.At the same time, a total disk number “N” is increased by 1. Then, theupdated classification data is statistically analyzed in a step S25. Forexample, the circulation of the forged products is confirmed when theoccurrence n_(ij) of a specific disk pattern (ij) is larger than theaverage occurrence no of other patterns by a predetermined threshold.The rule β stored in the ROM 11 determines this predetermined threshold(e.g., 3σ). Thus, in a step S26, it is checked whether the value(n_(ij)−n₀) is equal to or larger than 3σ, where σ represents thestandard deviation. When the judgement result is “NO” in the step S27,the decision of the forged product circulation is postponed as the totalnumber of the forged products is small. Thus, the distributionadministrating center 100 returns the inspection result “YES” to theterminal (refer to the step S15 in the flowchart of FIG. 13). On theother hand, when the judgement result is “YES” in the step S26, it isconcluded that a significant amount of forged products have been alreadycirculated in the market at this timing. Thus, in a step S28, thedistribution administrating center 100 returns the inspection result“NO” to the terminal.

According to the above-described embodiment, the distributionadministrating center 100, serving as a center office equipped with ahost computer, performs the first and second true-false judgements.There is no necessity of providing the memories 11 and 12 in eachterminal in the wholesaler 103 and the retailer 104. Accordingly, thesystem cost is inexpensive. The memories 11 and 12 storing the secretinformation can be safely managed at the center office which is isolatedfrom the market. The distribution administrating center 100 can beprovided for each manufacturer 102 or commonly used by a group ofmanufactures 102. It is preferable that the distribution administratingcenter 100 periodically transmits the information to manufactures 102 orsoftware makers 101. In this case, the information may include themanufactured amount of the disk 1, detailed allocation of thecombination patterns of the images “A” and “B”, and the presence of theforged products.

Returning to the actual market, there are some problems to be solved.For example, some of the forged products will circulate through amail-order selling channel, a door-to-door selling channel, or a streetstall other than the retailer 104. An ill-intentioned retailer 104 willnot mind to unlawfully sell the forged disks. No information istransmitted to the distribution administrating center 100 since theterminals are not used in these cases.

To solve this kind of problems, the present invention proposes a systemincluding a modem and a communication software incorporated in the diskrecording/playback system of the customer 105 (FIG. 12).

FIG. 15 is a flowchart showing the processing performed in the diskrecording/playback system of the customer 105. First, in a step S31, theinitialization is performed. Then, in a step S32, the images “A” and “B”are read from the disk 1 to perform the true-false judgement. Then, in astep S33, the communication line is connected via the modem between thedisk recording/playback system and the distribution administratingcenter 100. In a step S34, the detected combination of the images “A”and “B” is transmitted to the distribution administrating center 100.The distribution administrating center 100 checks the receivedinformation with the registered data. Then, the distributionadministrating center 100 returns the inspection result to the terminal.Thus, in a step S35, the disk recording/playback system receives ananswer signal of “GO” or “STOP” returned from the distributionadministrating center 100. Then, in a step S36, the diskrecording/playback system allows the playback of the disk 1 in responseto the “GO” signal and displays an error message or ejects the disk 1 inresponse to the “STOP” signal.

FIG. 16 is a flowchart showing the processing performed in thedistribution administrating center 100. The distribution administratingcenter 100 receives the information from the disk recording/playbacksystem in a step S40 to perform the first true-false judgement. Thecombination of the images “A” and “B” transmitted from the diskrecording/playback system is compared with the image patterns α, i.e.,25 (=5×5) patterns, stored in the ROM 11 in a step S41. If nocoincidence is found (NO in the step S41), it is concluded that theinspected disk 1 is a forged product. Thus, in step S47, thedistribution administrating center 100 returns the “STOP” signal to thedisk recording/playback system.

If any coincidence is found (YES in the step S41), the distributionadministrating center 100 performs the second true-false judgement. Morespecifically, in a step S42, the detected combination of the transmittedimages “A” and “B” is classified into the corresponding one of the 5×5patterns of the image patterns α. Then, in a step S43, the RAM 12increments a count value of the identified pattern as shown in FIG. 5.At the same time, a total disk number “N” is increased by 1. Then, theupdated classification data is statistically analyzed in a step S44. Forexample, the circulation of the forged products is confirmed when theoccurrence n_(ij) of a specific disk pattern (ij) is larger than theaverage occurrence n₀ of other patterns by a predetermined threshold.The rule β stored in the ROM 11 determines this predetermined threshold(e.g., 3σ). Thus, in a step S45, it is checked whether the value(n_(ij)−n₀) is equal to or larger than 3σ, where σ represents thestandard deviation. When the judgement result is “NO” in the step S45,the decision of the forged product circulation is postponed as the totalnumber of the forged products is small. Thus, the distributionadministrating center 100 returns the “GO” signal to the diskrecording/playback system (refer to the step S35 in the flowchart ofFIG. 15). On the other hand, when the judgement result is “YES” in thestep S45, it is concluded that a significant amount of forged productshave been already circulated in the market at this timing. Thus, in astep S47, the distribution administrating center 100 returns the “STOP”signal to the disk recording/playback system (refer to the step S35 inthe flowchart of FIG. 15).

This system is applicable not only to so-called standalone type diskrecording/playback systems but also to built-in disk recording/playbacksystems of the personal computers. The communication hardware andsoftware of the personal computers can be effectively used in this case.

The above-described forged product detecting system can be flexiblymodified according to the type of distribution channel. For example, asshown in FIG. 17, it is possible to connect each of the wholesaler 103,the retailer 104, and the customer 105 to the distributionadministrating center 100 via a unidirectional communication line,instead of using the bidirectional communication line. This systemsufficiently works in roughly checking the circulated condition of theforged products.

The presently available cable communications, radio communications,analog lines and digital lines are usable for the communications in theabove-described forged product detecting system. The high-speed digitallines, such as ISDN, are preferably used for the bidirectionalcommunications. However, the analog lines will be sufficient for theunidirectional communications. Regarding the lines, the directconnection is preferable. However, it is possible to establish thecommunication line via the Internet or any other commercially availablecommunication network. The E-mail or telex will be used in theunidirectional communication, since the time lag of few days will beallowed. Furthermore, when a product managing system is alreadyinstalled in the wholesaler 103 or in the retailer 104, thebidirectional communication function of the existing product managingsystem will be utilized for the forged product detecting system. Whenthe customer 105 likes the outdoor use of the playback system, aportable telephone or a similar handy phone will be used as acommunication device for transmitting the information to thedistribution administrating center 100.

Furthermore, when the information is sent from the wholesaler 103, theretailer 104 or the customer 105 to the distribution administratingcenter 100, it is preferable to add identification data, such as a codenumber, address, telephone number, and a network ID. These data will beeffectively used in the succeeding procedure performed in thedistribution administrating center 100.

Hereinafter, the detailed arrangement of the disk 1 will be explainedwith reference to cross-sectional views. FIG. 18 shows a CD including asubstrate 201, a first recording layer 202 formed on the substrate 201,a protection layer 203 formed on the first recording layer 202, and asecond recording layer 204. The main information including the firstimage “A” is recorded in the first recording layer 202. The second image“B” is recorded in the second recording layer 204. More specifically,the substrate 201 is a polycarbonate or acrylic or polyolefine substratehaving a thickness of 1.2 mm. The image “A” is a fine pit or groovepattern formed on the upper surface of this substrate 201 by stamping.The first recording layer 202 contains a metal selected from the groupconsisting of aluminum, gold, silver, copper, titanium, chrome, nickel,tantalum, molybdenum, iron and silicon which has a high reflectivity, ortheir alloys. The protection layer 203 is, for example, made of aultraviolet ray curable resin for protecting the first recording layer202. The layer 204 is formed by screen printing or offset printing toform the image “B.” The first recording layer 202 has a lowertransmissivity to prevent the leakage of information between the firstrecording layer 202 and the second recording layer 204.

FIG. 19 shows a DVD of 4.7 GB which has a bonded-substrate structure.The main information including the first image “A” is recorded on afirst substrate 201 a (0.6 mm thick). A first recording layer 202 isformed on the upper surface of the first substrate 201 a. A protectionlayer 203 is formed on the first recording layer 202. A second substrate201 b (0.6 mm thick) is bonded on the protection layer 203 via anadhesive layer 205 (e.g., ultraviolet ray curable type). A secondrecording layer 204, in which the second image “B” is formed, is partlyprinted on the upper surface of the second substrate 201 b.

FIG. 20 shows another DVD of 4.7 GB which has a similar bonded-substratestructure. The main information including the first image “A” isrecorded on the first substrate 201 a (0.6 mm thick). The firstrecording layer 202 and the protection layer 203 are successively formedon the upper surface of the first substrate 201 a. On the other hand,the second recording layer 204 is partly printed on the lower surface ofthe second substrate 201 b (0.6 mm thick). A shielding layer 206 isformed entirely along the lower surface of the second substrate 201 bincluding the printed second recording layer 204 by white ink orwhole-surface screen printing. The protecting layer 203 and theshielding layer 206 are bonded by the adhesive layer 205 (ultravioletray curable type). The shielding layer 206 conceals the rolling patternspeculiar to the adhesive, thereby eliminating the reading error by theCCD line sensor 2.

FIG. 21 shows another DVD of 4.7 GB which has another similarbonded-substrate structure. The main information including the firstimage “A” is recorded on the first substrate 201 a (0.6 mm thick). Thefirst recording layer 202 and the protection layer 203 are successivelyformed on the upper surface of the first substrate 201 a. The secondimage “B” is formed on the lower surface of the second substrate 201 bby stamping. The second recording layer 204 is formed on the lowersurface of the second substrate 201 b. The second recording layer 204contains a metal selected from the group consisting of aluminum, gold,silver, copper, titanium, chrome, nickel, tantalum, molybdenum, iron andsilicon which has a high reflectivity, or their alloys. The firstrecording layer 202 and the second recording layer 204 are bonded by theadhesive 205 of adhesive sheet type. According to this arrangement, theCCD line sensor 2 can be replaced by the pickup lens 3. It is alsopossible to replace the first recording layer 202 by a semitransparentlayer, e.g., a thin metallic film or a thin dielectric layer. In thiscase, it becomes possible to read the information of the secondrecording layer 204 through the first recording layer 202 by the pickuplens 3 placed near the substrate 201. In other words, the total numberof the required sensors can be reduced to only one (i.e., single pickuplens 3).

The present invention is not limited to the above-described CD and DVDs,and therefore can be applied to MO disks, phase-change type disks, andwrite once type disks. In this case, the first recording layer 202 isreplaced by a conventional MO medium (e.g., a multilayered structure ofSiO·TbFeCo·SiN·Al). The present invention can be applied to amultilayered disk having three or more information surfaces. In thiscase, the images “A” and “B” are arbitrarily disposed on selectedsurfaces. The thickness of the disk substrate is not limited to 0.6 mmor 1.2 mm.

FIG. 22 shows a read only HDTV (high-definition television) diskincluding a 0.8 mm substrate 201 on which the main information includingthe first image “A” is recorded. The first recording layer 202 and theprotection layer 203 are successively formed on the upper surface of thesubstrate 201. The second recording layer 204, in which the second image“B” is formed, is printed along the cylindrical side surface of thesubstrate 201 by bar-code printing or by stamping. According to thisarrangement, the protecting layer 203 has a free upper surface on whichanother substrate can be bonded to realize a high-density disk.

It is preferable that the image “A” is recorded by a special recordingmethod so as not to be easily deciphered by the third parties. Forexample, the image “A” is recorded in a lead-in area, a lead-out area,or a stamp area describing the disk number. It is also preferable toincorporate the image “A” as a low-frequency wobble signal into the maininformation. It is also preferable to incorporate the image “A” as anasymmetry variation of the RF signal. It is also possible to incorporatethe image “A” as an electric watermark into the main image or videoinformation. Moreover, the present invention can be combined with anyexisting anti-forgery method.

Furthermore, instead of using the ROM 11, it is possible to record theregistered image patterns “α” in an enciphered format on a specific areaof the disk 1.

FIG. 23 shows a disk manufacturing facility for recording the firstimage “A” into the main information and printing the second image “B” tothe disk 1. There are a total of five blank carrier manufacturing linesA1 to A5 each recording the main information including a designatedpattern of the image “A” on a blank disk. Similarly, there are a totalof five printing lines B1 to B5 each printing the designated pattern ofthe image “B” on the disk 1. A connecting device 21, interposed betweenthe blank carrier manufacturing lines A1-A5 and the printing linesB1-B5, randomly connects one blank carrier manufacturing line to oneprinting line to manufacture the 25 patterned disks 1. It is possible tointerpose a mixing device 22 between the blank carrier manufacturinglines A1-A5 and the connecting device 21, as shown in FIG. 24.

This invention may be embodied in several forms without departing fromthe spirit of essential characteristics thereof. The present embodimentsas described are therefore intended to be only illustrative and notrestrictive, since the scope of the invention is defined by the appendedclaims rather than by the description preceding them. All changes thatfall within the metes and bounds of the claims, or equivalents of suchmetes and bounds, are therefore intended to be embraced by the claims.

1. A playback and communication system, comprising: a playback devicefor reading information stored in a predetermined region of aninformation recording medium by using an optical pickup device, and acommunication device for establishing a communication line between saidplayback device and an external device to transmit the information readout by said playback device to said external device via saidcommunication line.
 2. An information processing system, comprising: areceiving device for receiving information via a communication line froman apparatus which includes a playback device for reading saidinformation from a predetermined region of an information recordingmedium by using an optical pickup device and a communication device forestablishing said communication line; a processor for processing theinformation received by said receiving device; and a transmitting devicefor outputting the information processed by said processor.